(a) Field of the Invention
The present invention relates to a fuel cell component and a manufacturing device, and more particularly, to coat an adhesive to a portion of a gas diffusion layer and to attach the coated adhesive to a membrane-electrode assembly (MEA) and a subgasket to reduce cost and maintain the position of the adhesive from moving toward an electrode to improve performance.
(b) Description of the Related Art
Typically, in a polymer electrolyte fuel cell, a membrane-electrode assembly (MEA) is a main component disposed in the innermost fuel cell. In particular, a 3-layer membrane-electrode assembly (MEA) includes a structure in which catalyst layers for a fuel electrode and an air electrode are disposed on both surfaces of the electrolyte membrane is. A 5-layer membrane-electrode assembly (MEA) includes a structure in which a gas diffusion layer (GDL) is stacked on the exterior portion of the catalyst layer.
The MEA includes a polymer electrolyte membrane, the catalyst layer (e.g., or an electrode) disposed on both sides of the polymer electrolyte membrane and a subgasket. The subgasket has a thickness greater than a thickness of the catalyst layer that facilitates the handling of the MEA and is bonded to both sides of an edge area of the polymer electrolyte membrane and is an inert polymer film such as polyethylene (PE)), polyethylene naphthalate (PEN) etc. A single unit cell is formed when a separator that has a flow field formed therein to supply fuel and to exhaust water generated by a reaction is stacked on the exterior of the gas diffusion layer. A fuel cell stack of desired size is formed when the unit cells are stacked.
A method for manufacturing the MEA includes a method for manufacturing the 5-layer membrane-electrode assembly using a catalyst coated on GDL (CCG). A method for manufacturing the 3-layer membrane-electrode assembly using a catalyst coated on membrane (CCM) method. The CCG method directly coats the catalyst layer on the gas diffusion layer to bond the coated catalyst layer to the polymer electrolyte membrane. The CCM method directly coats the catalyst layer on the polymer electrolyte membrane.
According to the CCG method or a catalyst coated on substrate (CCS) method that directly coats the catalyst layer on the gas diffusion layer. After the catalyst layer is directly coated on the gas diffusion layer bonding between the catalyst layer and the polymer electrolyte membrane is performed by a heat press process (e.g., or a thermocompression bonding process) to manufacture the 5-layer membrane-electrode assembly. According to the CCM method, after the gas diffusion layer is stacked on the catalyst layer, a separate process that presses the gas diffusion layer stacked to bond the gas diffusion layer stacked to the catalyst layer is required. In other words, when unit cells including the 3-layer membrane-electrode assemblies are stacked in a stack manufacturing process using automatic equipment after the 3-layer membrane-electrode assembly is manufactured using the CCM method, the process that bonds the gas diffusion layer to the catalyst layer is required.
The CCM method has limited productivity for mass production of the fuel cell stack. When the gas diffusion layer is temporarily bonded to the 3-layer MEA by the thermocompression bonding process, an interface where a fuel cell reaction occurs is formed between the catalyst layer and the gas diffusion layer and an interface is formed between the subgasket and the gas diffusion layer. However, the bonding force is weak between the catalyst layer and the gas diffusion layer or the subgasket and the gas diffusion layer. When the keeping (stand-by) duration for mass production of the fuel cell stack is increased the bonding force becomes further weakened. Accordingly, the catalyst layer may be separated from the gas diffusion layer. One approach to increase the bonding force is to coat an ionomer such as Nafion on the gas diffusion layer prior to the thermocompression thereof to the catalyst layer. However, since the interface of the gas diffusion layer that contacts the catalyst layer has a hydrophilic property, the bonding force is not significantly increased.
The above information disclosed in this section is merely for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.